具有Gemini表面活性ATRP引发剂的合成

以2-溴异丁酰溴、N,N-二甲基乙醇胺、1,6-二溴己烷为主要原料,通过两步反应合成了一种新型具有Gemini表面活性的ATRP引发剂——N1,N6-双[2-(2-溴异丁酰氧基)乙基]-N1,N1,N6,N6-四甲基己烷-1,6-二溴化铵,总收率70%,其结构经1H NMR,IR和元素分析表征。     

具有光引发活性ATRP引发剂的选择性合成

4-甲基二苯甲酮在HBr/H2O2/光照体系中完成溴化合成了具有光引发活性的原子转移自由基聚合(ATRP)引发剂 --4-溴甲基二苯甲酮(产率88%)和4-二溴甲基二苯甲酮(产率96%),其结构经NMR和IR表征.     

采用ATRP合成天然橡胶接枝共聚物——Ⅰ. ATRP大分子引发剂的制备

通过环氧化反应在天然橡胶分子链上引入环氧基制得环氧化天然橡胶(2);利用环氧基的反应活性,2与2-溴-2-甲基丙酸发生开环反应合成了原子转移自由基聚合(ATRP)大分子引发剂——天然橡胶-g-(2-溴-2-甲基丙酸),其结构经1H NMR和IR表征.     

具有阳离子表面活性ATRP引发剂的合成

以2-溴异丁酰溴、2-溴乙醇、6-氯-1-己醇及N,N-二甲基正十二烷基胺为主要原料,分别通过两步或三步反应合成了具有阳离子表面活性的原子转移自由基聚合(ATRP)引发剂——N-[2-(2-溴-2-甲基丙酰氧基)乙基]-N,N-二甲基正十二烷基溴化铵或N-[6-(2-溴-2-甲基丙酰氧基)己基]-N,N-二甲基正十二烷基碘化铵,其结构经1H NMR,13C NMR,IR和元素分析表征。     

具有表面活性 ATRP 引发剂的合成及应用

以4-氯甲基苯甲酸、1,10-癸二醇、顺丁烯二酸酐为主要原料,通过三步反应合成了具有阴离子表面活性的原子转移自由基聚合(ATRP)引发剂:4-(10-(4-氯甲基苯甲酰氧基)癸氧基-4-氧代-2-磺酸基丁酸二钠(3).第一步选择性酯化的分离产率为81%,第二步酯化的分离产率为64%,第三步最终产物的收率为91%.对合成...     

三臂ATRP引发剂的合成及应用

分别以三乙醇胺、三聚氰胺为原料,通过酰化反应合成了三种具有配体功能的三臂原子转移自由基聚合(ATRP)引发剂:三[2-(2-溴异丁酰氧基)乙基]胺,三[2-(4-氯甲基苯甲酰氧基)乙基]胺和2,4,6-三(2-溴异丁酰胺基)-1,3,5-三嗪,收率分别为81%,69%和83%。以三[2-(2-溴异丁酰氧基)乙基]胺既作引发剂又作配体进行甲基丙烯酸甲酯(MMA)的ATRP乳液聚合,结果表明反应前期与中期具有活性/可控特征。     

具有表面活性ATRP引发剂的合成及其在无皂乳液聚合中的应用

以2-溴异丁酰溴、1,2-乙二醇、1,6-己二醇、顺丁烯二酸酐为主要原料,通过三步反应合成了具有阴离子表面活性的原子转移自由基聚合(ATRP)引发剂——4-[2-(2-溴-2-甲基丙酰氧基)乙氧基]-4-氧代-2-磺酸基丁酸二钠(1a)和4-[6-(2-溴-2-甲基丙酰氧基)己氧基]-4-氧代-2-磺酸基丁酸二钠(1b),其结构经1HNMR,IR和元素分析表征。用1引发无皂乳液聚合,研究结果表明反应是活性自由基乳液聚合,所得乳液非常稳定。     

ATRP大分子引发剂的合成及应用

原子转移自由基聚合(ATRP)是一种新型的可控/活性聚合技术,现已广泛应用于聚合物分子结构设计、无机材料表面修饰、蛋白质检测以及生物大分子的分离和杀菌防污等.在此类反应过程中涉及的三大要素:单体、引发体系(引发剂、催化剂、配位剂)及反应介质,其中核心要素为ATRP引发剂,其结构与性质是ATRP反应成败的决定因素之一.本文在综述了小分子引发剂的种类与性质及ATRP的反应机理的基础上,着重综述了近年来官能团反应法、偶联反应法及自由基聚合法制备ATRP大分子引发剂的最新进展.同时还综述了大分子引发剂通过ATRP反应在聚合物结构设计中的应用,以及对无机材料和生物材料的表面修饰的最新进展,最后对ATRP引发体系的未来发展与应用进行了展望.     

大分子ATRP引发剂α-卤烷基聚苯乙烯的合成及其引发的丙烯酸丁酯接枝聚合

通过酰基化、还原、酯化和卤代反应 ,在聚苯乙烯上引入α 卤烷基 ,使用FTIR、1 H NMR、1 3C NMR和GPC对产物进行表征 ,结果表明基团转化可以完全进行 ,整个过程中无交联等副反应 .其中α 溴乙基聚苯乙烯可作为原子转移自由基聚合的多功能度引发剂 ,由此引发丙烯酸正丁酯聚合生成梳状聚 (苯乙烯 g 丙烯酸正丁酯 )     

α-氯乙酰氧基大分子引发剂的合成及其引发原子转移自由基聚合

通过阴离子聚合制备了α－氯乙酰氧端基大分子引发剂。并用于引发（甲基）丙烯酸酯类单体进行“活性”／可控的原子转移自由基聚合（ＡＴＲＰ）。结果表明：酰化反应温度为６０℃,氯乙酰氯过量５倍和反应２４ｈ,酰化效率达到９９．８％,产物经红外和核磁共振表征,证明α－氯乙酰氧端基的结构。用此引发剂引发乙烯基单位进行ＡＴＲＰ,合成了ＰＳｔ－ｂ－ＰＭＡ和ＰＳｔ－ｂ－ＰＢＡ嵌段共聚物,其结构通过＾１Ｈ ＮＭＲ得到确证     

Investigation of the Formation of Squalene Oligomers Exposed to Ultraviolet Light and Changes in the Exposed Squalene as a Potential Skin Model

UV-induced oligomerisation of squalene was undertaken to indicate the potential for squalene-containing biological systems to exhibit rheology changes. DOSY NMR enabled the determination of the molecular weight (MW) range using Stokes–Einstein Gierer–Wirtz Estimation (SEGWE Calculator, University of Manchester). This approach was validated by Atmospheric Solids Analysis Probe Time of Flight Mass Spectrometry (ASAP TOF MS). To demonstrate the principle, both benzoyl peroxide and AIBN were used, separately, to initiate rapid, radical oligomerisation. Subsequent experiments in the absence of initiators compared the influence of UV wavelength and time on the resulting oligomer formation. To further model a relevant biological implication of this potentially chaotic UV oligomerisation, both saturated and unsaturated free fatty acids were added to squalene and exposed to UV at 285 nm and 300 nm to determine if cross oligomerisation could be observed. This representation of sebum evidenced the formation of a distribution of higher MW oligomers. Internal viscosity was normalised using the DMSO solvent, but to confirm that changes in rheology did not affect diffusion, a final experiment where fresh squalene was added to our oligomer mixture, representative of sebum, showed that unchanged squalene possessed the anticipated monomeric diffusion coefficient and hence MW. This work suggests, at least qualitatively, that UV-induced squalene oligomerisation can occur over time and that this may have a role in the behaviour of squalene on the skin.     

胶乳法溴化天然橡胶的结构与性能

在胶乳状态下制得不同溴含量的溴化天然橡胶产物,并采用傅里叶红外光谱和1H NMR核磁共振测试技术对胶乳法溴化天然橡胶（BNR）的结构进行了表征,用扫描电子显微镜对BNR的形貌进行了观察,考察了不同溴含量BNR的溶解性能和氮含量。红外光谱分析表明,天然胶乳溴化反应时发生了溴化取代和加成反应;1H NMR分析结果则证实存在C=C双键加成和亚甲基、甲基的溴化取代。 随着溴含量的增加,BNR产物逐渐变得硬而脆,最终呈粉末状,且粒径减小。 同一溴化天然橡胶产物在不同溶剂中的溶解能力由小到大依次为：四氯化碳、苯＜甲苯、二甲苯＜四氢呋喃＜三氯甲烷＜环己酮;在同一有机溶剂中BNR的溶解性能则随着溴含量的增加而增大。 BNR产物的含氮量随着溴含量的增加而减小,当溴含量为42％时,氮含量减小至0.10％。     

Natural Phenolic Compounds as Modifiers for Epoxidized Natural Rubber/Silica Hybrids

Silica is a popular filler, but in epoxidized natural rubber, can act as a cross-linking agent. Unfortunately, a high amount of silica is necessary to obtain satisfactory tensile strength. Moreover, a high amount of silica in ENR/silica hybrids is associated with low elongation at break. In our paper, we propose natural phenolic compounds, including quercetin, tannic acid, and gallic acid as natural and safe additional crosslinkers dedicated to ENR/silica hybrids to obtain bio-elastomers with improved mechanical properties. Therefore, toxic crosslinkers, such as peroxides or harmful accelerators can be eliminated. The impact of selected natural phenolic compounds on crosslinking effect, mechanical properties, color, and chemical structure of ENR/silica composite have been analyzed. The obtained results indicated that only 3 phr of selected natural phenolic compounds is able to improve crosslinking effect as well as mechanical properties of ENR/silica hybrids. Moreover, some of the prepared materials tend to regain mechanical properties after reprocessing. Such materials containing only natural and safe ingredients have a chance of becoming novel elastomeric biomaterials dedicated to biomedical applications.     

丁苯橡胶/天然橡胶复合体系动态力学性能

生热;动态力学损耗;丁苯橡胶/天然橡胶复合体系动态力学性能     

环氧化天然橡胶二次改性的研究进展

环氧化天然橡胶(ENR)分子链中存在易开环的反应性环氧基团,环氧基团的开环反应为ENR进行进一步的改性提供了极大的方便。ENR选择性氢化双键可以提高其抗热氧稳定性;ENR与胺类化合物和含磷化合物的反应,可以将防老剂和阻燃剂负载到ENR分子链上,从而达到在分子尺寸的分散;可以利用环氧基团的选择性氧化裂解制备NR基嵌段共聚物的前驱体遥爪型NR;通过环氧基团可以进行接枝改性其它聚合物;此外,分子链中的环氧基团使ENR与无机填料和其它极性聚合物共混相容性提高。     

氯化天然橡胶的等速升温热降解动力学

天然胶乳;氯化天然橡胶的等速升温热降解动力学     

Waxy Maize Starch Nanocrystals as Filler in Natural Rubber

Starch nanocrystals obtained from acid hydrolysis of waxy maize starch granules consist in crystalline nanoplatelets about 6–8 nm thick with a length of 20–40 nm and a width of 15–30 nm. New nanocomposite materials, i.e. natural rubber (NR) filled with waxy maize starch nanocrystals were processed by casting. Dynamic mechanical analysis has shown that starch nanocrystals were a good reinforcing agent for NR at temperatures higher than the glass transition temperature of NR. Tensile tests have shown that until a weight fraction of 20 wt%, this new filler presented the advantage to reinforce natural rubber without decreasing significantly the strain at break of the material. These properties may be due to both the morphological nature of starch nanocrystals, and the formation of a percolating starch nanocrystals network within the NR matrix, resulting from hydrogen bonding forces between starch aggregates.